package com.xiaoyang.interceptor;

import lombok.extern.slf4j.Slf4j;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.util.Objects;

/**
 * @author lichenyang
 * @create 2021-07-14 07:25
 *
 * 登录检查
 * 何时工作:
 * 1. 配置好拦截器要拦截哪些请求
 * 2. 将配置放到容器中
 *
 */
@Slf4j
public class LoginInterceptor implements HandlerInterceptor {

    /**
     * 目标方法执行之前
     * @param request
     * @param response
     * @param handler
     * @return true:放行, false:拦截
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        // 执行登录检查逻辑
        log.info("拦截的方法是:{}", request.getRequestURI());
        HttpSession session = request.getSession();
        Object loginUser = session.getAttribute("loginUser");
        if(Objects.nonNull(loginUser)){
            // 放行
            log.info("prehandle放行");
            return true;
        }
        // 拦截, 拦截成功后跳转到登录页面
        session.setAttribute("msg", "请先登录");
//        response.sendRedirect("/login.html");
        log.info("方法被拦截");
        return false;
    }

    /**
     * 目标方法执行后, 页面跳转前
     * @param request
     * @param response
     * @param handler
     * @param modelAndView
     * @throws Exception
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        log.info("postHandle 执行, modelAndView :{}", modelAndView);
    }

    /**
     * 页面跳转后
     * @param request
     * @param response
     * @param handler
     * @param ex
     * @throws Exception
     */
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        log.info("afterCompletion执行异常 ex:{}", ex);
    }
}
